A purpose

A simple written sentence, a brief snatch of conversation and I am way back in happier times. A short while ago someone told me that everybody has a purpose in life and I often wonder about that statement. Can it be true? If so, what is my purpose? Have I already achieved it? Am I still going to achieve it? Do I really have a purpose? How will I know what it is or if or when I achieved it? Is it something big, something small? I was told that the answer is within me. I would know what makes me happy, when I have done something good and worthwhile. But how do I measure “good” or “worthwhile”?? What standard do I use? How happy is “happy”? Is there something I can measure it against?
Then on the other hand, if I have served my purpose and achieved it, why am I still here on this planet? Surely if my purpose is served, I become redundant?? The outlook of living another 10-20 years without a purpose is a bleak one indeed!! Does that mean without a purpose I should now curl up in a corner and let the world go by? Should I accept more years of everyday being the same, no highs, no lows? Just an endless stream of days!
Just a simple statement, but it gives rise to a myriad of questions without answers. Do you think we each have a purpose on this planet? Examine your life and see if you can find an answer to this question. I can’t!!